1. Field of the Invention
This invention relates to mechanical sugar cane grab loaders generally. In particular, the invention relates to mechanical sugar cane grab loaders having an articulated grab, a boom for lifting the grab, and a pushpiler for pushing cane into bundles to be grabbed.
2. Description of the Prior Art
A general type of mechanical sugar cane grab loader uses a hydraulically actuated, articulated grab to collect or "grab" a bundle of sugar cane on top of the soil, a hydraulically actuated boom to lift the grab, and mechanical means for pushing the cane over the soil to form the bundle which is subsequently grabbed. The mechanical means may be referred to as pushpiler.
The main problem presented by the operation of mechanical sugar cane grab loaders is the significant amount of trash, including soil particles, gravel, stones, roots, etc., collected together with the sugar can by the action of the grab and the pushpiler when they penetrate the ground, over which is lying the sugar cane.
The state-of-the-art pushpilers normally used by grab cane loaders are generally constituted by two curved elements, concave shaped, terminated over the ground by two tips with knife edges, that scrape the soil and collect and bundle the sugar cane by pushing forward by the loader motion. These pushpilers are articulated on the front part of the loader structure, and their height controlled, generally by hydraulic means, by the operator. This way, the soil scraped by the pushpiler tips slides upwards along the curved elements of the pushpiler with the cane, and gets mixed with the bundle of cane.
The height above the ground of the pushpiler and the grab (during its closing movement) must be continuously and carefully controlled by the operator to minimize ground penetration and consequent soil contamination of the cane being loaded. This is a difficult and tiring operation, which results normally in a significant amount of trash present in the cane loaded, as already mentioned.